// 固定总时间的匀速运动
let maxWidth = document.documentElement.clientWidth || document.body.clientWidth,
    maxHeight = document.documentElement.clientHeight || document.body.clientHeight,
    box = document.getElementById('box')
animate(box, {
    left: maxWidth - box.offsetWidth,
    top: maxHeight - box.offsetHeight,
    // width: 50,
    // height: 50,
    fontSize: 10,
    opacity: 0.3,

},3000)